Device for cutting channels in stone or masonry



Nov. 8, i949 A. slp-TAR,

DEVICE FOR CUTTING CHANNELS IN STONE 0R MASONRY Filed May 25, .1947

3 Sheets-$heet l ZAK/,27?

Nov. 89 1949 A. slFTAR DEVICE FOR CUTTING CHANNELS IN STONE OR MASONRY Filed May 2s, 1947 /Nl/EN TOR:

ALEXANDER Sil-'TAR Nov. 8, E949 A. slFTAR 2,437,277

Y DEVICE FOR CUTTING CHANNELS IN STONE ORMASONRY Filed May 2.3, 1947 3 sheets-sheetI 5 /NVE/v rox?.-

ALFXANDE/e s/F me Patented Nov. 8, 1949 OFFICE DEVICE FOR CUTTING CHANNELS IN STONE OR MASONRY Alexander Siftar, Vienna, Austria Application May 23, 1947, Serial No. 750,081

In Austria June 1, 1946 (Cl. 1 25w14) 7 Claims.

The invention relates. to a device for cutting channels in stone and masonry and has for its object. to doy this. work in a. more exact and economic. mannery as has. been done hitherto.

The channels required for the laying of electric conductors and piping in masonry are usu ally cut; by hand with hammer and chisel, an operation which not only entails much labour, but does. not. give particularlyA regular results. The channels in almost everyl case become too large, causing unnecessary destruction of masonry, they piercing of chimneys and the use of an excessive amount of plaster.

The object of` my invention isl to avoid these drawbacks, to remove the dust, brought about by the work and to enable the worker to vary the width vand depth of the channel as desired.

One embodiment of the, device according to the invention is illustrated by way of example in the accompanying drawings in which Figs. 1 and 2 show the. device in longitudinal section and side elevation in two different operative positions,

Figs. 3 and 4 show a cross-section on line III of Fig.. 1. and anv end View and Fig. shows a detail to a large scale.

A housing I for the gearing is constructed as a carriage and is for this purpose provided at opposite sides with pairs of arms 2,l 2' and 3, 3'. In the arms 2, 2' is supported an. axlev 4 for rollers 5 and in the arms 3, .3 a Screw Ibolt 6 .for a stirrup 1, in the side members of which is supported an axle 8 for rollers 9, I0. In the upper part of the housing main shaft Il driven by a motor 62 is supported in longitudinal and transverse ball bearings I2, I3. A worm I4 mounted on the shaft II drives a worm wheel I5 of a shaft I6 connected to a spur wheel I1. The latter wheel meshes with a spur wheel I8 which is mounted on a shaft I9, as is also a spur wheel which meshes with a spur `wheel 2| mounted loosely on the shaft I6. The spur wheel 2| meshes with a spur wheel 22 mounted on a hollow shaft 23 which also supports the tool. The tool consists of a disc-shaped milling cutter 24 which is removably xed onther shaft 23 by means of a key 25. The milling cutter is securely held in this position by the disc 26 of a clamping screw 21 which extends through the hollow shaft 23 and is provided at its other end with a nut and (lock nut covered by a cap 28.

To the housing I are screwed at the places where the main shaft passes through its sides sleeves 29, 30, in which are housed coupling parts for connecting a flexible shaft and an arrangement for removing the dust by suction. In the' sleeve 29 is guided the terminal piece 3| of the sheath of the flexible shaft 32, the coupling piece 33 of which latter is pushed on to the end of the main shaft II and secured by a key'.v In order to prevent the terminal piece 3l from slipping out, there is inserted into it a spring shackle 34 which with a pin 35 engages in holes of the terminal piece 3| and of the sleeve 29.

Over the sleeve 3D is slipped the hub of a casing 3B of the arrangement for removing the dust by suction, where it is secured by means of a spring shackle 3l which engages with a pin 33 in holes in the sleeve 3u and the casing 35. The rotor 39 with the fan blades is pushed with its hub 45 on to the end of the main shaft.

The housing I is adapted to the space required for the gearing and to the shape of its elements and supports at the top two fork-shaped members 4I, between which the handle 42 is fixed. At each end of the handle is a change-.over switch 43, 43', which are so positioned that they can be actuated by the thumb for switching on thecurrent fed to the motor through a cable 44.

In order to be able to vary the depth of the mllledvin channel, the stirrup 'l supports with one oi. its arms a set of clutch teeth 45, for engagernent with which is provided a set of coun terteeth 46 formed on a plate 41 which .is .fixed to the arm 3 and has a graduated are 55. Between the other arm of the stirrup 1 and the arm 3 is a helical spring 48 Orl the bolt 6 and. at the end of the beit 6 on adjusting nut 49.

The. axle 8 has at that .end which is nearest the milling cutter a threaded collar 5D, on to which the roller IIJ is screwed with its hub front of its bearing in. the stirrur.r The hub has an inwardly projecting .annular flange 5I which forms the mark for enacting with a scale 52 provided on the axle 8. On the outside surface of the roller I0 is xable by means of a bayonet catch arrangement 53 a disc 54 which @forms a wheel flange for the roller, The milling cutteris surrounded by a cup-shaped casing 66 which is fixed to the housing I, is open at vthe .bottom and is provided at the top with a branch 51, to which a flexible tube (not shown) leading to the casing 56 of the suction arrangement can be attached. From the suction arrangement-a further flexible tube leads to a dust-collecting vessel. On the cylindrical wall of the casing 5.6 are slidable opposite one another two circular 'slide valve members 58, 59 which are stirrupshaped and mounted so as to be capable of swinging round the casing 56. Their cilindri cal central parts can, when the device is in D- eration, cover the opening of the casing 56 with the exception of a narrow gap, so that the suction arrangement can operate effectively. The slide valves are acted on by a spring BIJ in the closing sense and bear against the surface of the masonry with rollers 61.

The device operates in the following manner:

According to the depth to which the channel is to be cut the stirrup 'l is adjusted on the graduated arc 55 which gives the depth of channel directly in millimetres, which adjustment can be y effected after easing the nut 49 and turning the stirrup which is then secured in the new position by tightening the nut again. In Fig. 1 the position of the stirrup for the greatest depth of channel is shown, in the present case 25 mm. In Fig. 5 this position is shown in full lines, the adjustment to the smallest depth of channel, 5 mm., being indicated by dot and dash lines. The latter position is also shown in Fig. 2.

After the current has been switched on, the device is moved across the masonry along a marked-out line, either directly with one of the rollers or with a specially provided mark. The smallest width of channel is determined by the width of the milling cutter. In order to cut Wider channels, the device is guided along an already cut channel in such a manner that the wheel flange 54 runs along one wall of the channel. The milling cutter will then, owing to its distance from the wheel flange, bite into the masonry on the other side of the channel and widen the latter. The amount of this widening can be selected by displacing the roller I0 on the threaded collar 50 along the scale 52. In the present case the maximum amount, by which the channel can be widened, corresponds to double the width of the milling cutter. In the illustration in Fig. 4, assuming the milling cutter to be 12 mm. wide, the device is set to cut a channel 18 mrn. wide, that is, in the second cutting operation an additional 6 mm. will be cut out of the masonry- Working out the channel by means of milling cutters makes it possible to limit very accurately the width and depth of the channel with the minimum expenditure of labour and waste of material. The regularity obtained is of course of advantage in the laying of the conductors.

The motor may be placed on the ground, mounted on the ladder or even carried on the back. When the device is not to be used for cutting channels in walls, but is to be run along a horizontal surface, for instance the top surface of a stone, the motor maybe combined with the device.

The arrangement for removing the dust by suction enables work to be carried out without detrimentally affecting the health of the worker and without the nuisance caused by scattered dust.

The possibility of attaching the flexible shaft and the suction arrangement to either end of the main shaft at will provides the advantage of the worker being independent of the direction of rotation of the motor and therefore not bound to one direction in guiding the apparatus.

I claim:

1. A machine for cutting a groove in stones and masonry comprising a carriage adapted to travel over the surface of the stone, a rotatory cutting tool mounted on the carriage, a main shaft, speed reducing gears interposedbetween said main shaft and said cutting tool, identical coupling means provided at each end of said main shaft, a flexible shaft, and an exhauster,

both said flexible shaft and exhauster being adapted to be connected to either of said coupling means.

2. A machine for cutting a groove in stones and masonry comprising a carriage adapted to travel over the surface of the stone, a rotatory cutting tool mounted on the carriage, a main shaft, speed reducing gears interposed between said main shaft and said cutting tool, a flexible drive shaft coupled to one end of said main shaft. a roller connected with said carriage, said carriage comprising a housing for said reducing gears, a stirrup member pivoted to said housing, a set of rollers pivoted to said stirrup member, and a toothed clutch connected with said stirrup member for adjustably positioning it on said housing.

3. A machine for cutting a groove in stones and masonry comprising a carriage adapted to travel over the surface of the stone, a rotatory cutting tool mounted on the carriage, a main shaft, speed reducing gears interposed between said main shaft and said Icutting tool, a flexible drive shaft coupled to one end of said main shaft and a roller connected with said carriage and lbeing adjustable in axial direction, said roller having a flange extending into the groove cut by said machine.

4. A machine for cutting a groove in stones and masonry comprising a carriage adapted to travel over the surface of the stone, a rotatory cutting tool mounted on the carriage, a main shaft, speed reducing gears interposed between said main shaft and said cutting tool, a flexible drive shaft coupled to one end of said main shaft, a roller shaft .connected with said carriage, a roller screwed on said roller shaft and having a fiange extending into the groove cut by said machine, said roller having an extension movable freely around said roller shaft, and said shaft having a scale for determining the axial position of said extension.

5. A machine for cutting a groove in stones and masonry comprising a carriage adapted to travel over the surface of the stone, a rotatory cutting tool mounted on the carriage, a main shaft, speed reducing gears interposed between said main shaft and said cutting tool, a flexible drive shaft coupled to one end of said main shaft, an electric motor connected to and driving said exible shaft, a handle connected with said carriage, and a change-over switch disposed on said handle and interposed in the wiring of said motor.

6. A machine for cutting a groove in stones and masonry comprising a carriage adapted to travel over the surface of the stone, a rotatory cutting tool mounted on the carriage, a main shaft, speed reducing gears interposed between said main shaft and said cutting tool, a flexible drive shaft coupled to one end of said main shaft, a roller connected with said carriage, said carriage comprising a housing for said reducing gears, a stirrup member pivoted to said housing, a set of rollers pivoted to said stirrup member, a toothed clutch connected with said stirrup member for adjustably positioning it on said housing, and position indicating means provided on said stirrup member and on said housing and indicating the relative position of said stirrup member and said housing.

7. A machine for cutting a groove in stones and masonry comprising a carriage adapted to travel over the surface of the stone and including a casing, a main shaft and speed reduction gears driven thereby and disposed in said casing, an operating shaft driven by one of said gears and laterally protruding from said casing, a rotarycutting tool mounted on said operating shaft outside of said casing, a substantially cylindrical hood covering said cutting tool and halving an opening where said cutting tool is doing the cutting, two segmental cover members connected with said hood swingably about the axis of rotation of said cutting tool for adjusting said opening in accordance with the cutting depth of said tool, and a ,coil spring disposed around the axis of rotation of said tool and connected with said cover mem-bers and tending to move said members in opposite directions for closing said opening.

ALEXANDER SIFI'AR.

REFERENCES CITED The following references-are of record in the le of this patent:

UNITED STATES PATENTS 

